U.S. patent application number 12/732517 was filed with the patent office on 2011-09-29 for enhancing the effectiveness of energy harvesting from flowing fluid.
This patent application is currently assigned to Schlumberger Technology Corporation. Invention is credited to Giorgia Bettin, Jahir A. Pabon.
Application Number | 20110233936 12/732517 |
Document ID | / |
Family ID | 44655516 |
Filed Date | 2011-09-29 |
United States Patent
Application |
20110233936 |
Kind Code |
A1 |
Pabon; Jahir A. ; et
al. |
September 29, 2011 |
ENHANCING THE EFFECTIVENESS OF ENERGY HARVESTING FROM FLOWING
FLUID
Abstract
An apparatus and method to enhance the efficiency of an energy
harvesting device is disclosed. A modulator module creates
fluctuations in the flow at a predetermined frequency or group of
frequencies and these fluctuations increase mechanical vibrations
which are then harvested by an energy harvesting module.
Inventors: |
Pabon; Jahir A.; (Newton,
MA) ; Bettin; Giorgia; (Lexington, MA) |
Assignee: |
Schlumberger Technology
Corporation
Cambridge
MA
|
Family ID: |
44655516 |
Appl. No.: |
12/732517 |
Filed: |
March 26, 2010 |
Current U.S.
Class: |
290/54 |
Current CPC
Class: |
F04B 47/02 20130101;
E21B 41/0085 20130101; F03G 7/08 20130101 |
Class at
Publication: |
290/54 |
International
Class: |
F03B 13/10 20060101
F03B013/10 |
Claims
1. A method to enhance the efficiency of an energy harvesting
device comprising the steps of: increasing fluctuations of a fluid
with a modulator module; with a housing defining an inner volume
though which the fluid is permitted to traverse from a first
opening to a second opening, generating vibrations in the housing
from the increased fluid fluctuations; and harvesting energy
upstream from the generated vibrations.
2. The method of claim 1 wherein the modulator module is configured
to modulate fluid flow.
3. The method of claim 2 wherein the modulated fluid flow is at a
predetermined frequency or group of frequencies.
4. The method of claim 1 wherein frequency of the fluctuations is
determined based on a natural frequency of vibrations of the
housing.
5. The method of claim 1 wherein a modulation frequency of a
modulation signal generated by the modulation module is selected to
be substantially equal to the energy harvesting devices resonance
frequency.
6. The method of claim 5 wherein the predetermined frequency or
group of frequencies increases amplitude of the fluctuations of the
fluid.
7. The method of claim 6 wherein the increase in amplitude of the
fluctuations of the fluid is small enough to minimally affect fluid
flow.
8. The method of claim 1 wherein a modulation frequency of a
modulation signal generated by the modulation module is selected to
be substantially equal to the vibrations of the housing resonance
frequency.
9. The method of claim 1 wherein the modulator module modulates a
power signal to an artificial lift device.
10. The method of claim 9 wherein the artificial lift device is an
electric submersible pump mounted in said housing;
11. The method of claim 1 wherein the housing is a production
tubing.
12. The method of claim 1 wherein the energy is harvested with one
or a plurality of energy harvesting modules.
13. The method of claim 12 wherein the one or a plurality of energy
harvesting modules are disposed on a production tubing.
13. The method of claim 1 wherein the modulator module modulates
fluid flow at a predetermined frequency or group of frequencies to
match the frequency of one or a plurality of the energy harvesting
module.
15. The method of claim 1 wherein the generated vibrations are from
structural vibrations of the production tubing.
16. The method of claim 1 wherein the generated vibrations are from
vibrating a power generating assembly on the housing in response to
the fluid flow through the housing.
17. The method of claim 16 wherein the power generating assembly is
a vibrating sleeve.
18. The method of claim 16 wherein the power generating assembly is
a flow obstacle mounted on the end of the housing.
19. The method of claim 1 wherein the modulator module is a flow
restrictor modulator module.
20. The method of claim 19 wherein the flow restrictor modulator
module is modulated to the energy harvesting device frequency
creating resonance.
21. The method of claim 1 wherein the energy harvesting device
provides power to a flow monitoring module.
22. The method of claim 1 wherein the energy harvesting device
provides power to a flow control module.
23. An apparatus for enhancing the efficiency of an energy
harvesting device comprising: a modulator module for increasing
fluctuations of a fluid; a housing defining an inner volume though
which the fluid is permitted to traverse from a first opening to a
second opening, generating vibrations in the housing from the
increased fluid fluctuations; and harvesting energy upstream from
the generated vibrations.
24. An apparatus for enhancing the efficiency of an energy
harvesting device comprising: a housing having at least one wall
defining an inner volume though which fluid is permitted to
traverse from a first opening to a second opening; means for
increasing the instability of said fluid; wherein the housing
vibrates from the increased fluid instability; and harvesting
energy upstream from the generated vibrations;
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This disclosed subject matter is generally related to
harvesting energy, and more particularly to enhancing the
efficiency of downhole energy harvesting devices by creating flow
fluctuations.
[0003] 2. Background of the Invention
[0004] In order to recover natural resources from subterranean
formations it is often necessary to perform tasks related to
exploration, monitoring, maintenance and construction in remote
locations that are either difficult or impractical for personnel to
reach directly. For example, boreholes may be drilled tens of
thousands of meters into the earth, and in the case of offshore
drilling; the borehole may be thousands of meters under water. One
of the technical challenges to performing tasks in such remote
locations is providing power to equipment. It is known to power
downhole and undersea equipment via stored energy or wireline
connection to the surface. However, both of these techniques have
disadvantages. For example, a wireline connection to the surface
limits that distance at which the equipment can operate relative to
the energy source, and may require a relatively significant portion
of the limited volume of a borehole. Using stored energy avoids
some of the disadvantages of a wireline connection to the surface,
but relatively little energy can be stored in comparison to
requirements because of size limitations. For example, the
available volume in a borehole environment is small. Further, both
wireline connections to the surface and stored energy techniques
require the presence of operators, e.g. a surface vessel to either
provide the wireline energy or recharge the energy storage
means.
[0005] Various techniques associated with energy production are
known. The presently disclosed subject matter addresses the
problems of the prior art by enhancing the energy available for
harvesting and therefore the energy harvested.
SUMMARY OF THE INVENTION
[0006] According to embodiments, a method to enhance the efficiency
of an energy harvesting device is disclosed. The method comprises a
number of steps which include in one non-limiting example
increasing the fluctuations of a fluid flow with a modulator
module, with a housing defining an inner volume though which the
fluid is permitted to traverse from a first opening to a second
opening, generating vibrations in the housing from the increased
fluid fluctuations; and harvesting energy upstream from the
generated vibrations.
[0007] In a further embodiment an apparatus for enhancing the
efficiency of an energy harvesting device is disclosed. This
apparatus comprises in one non-limiting example a modulator module
for increasing fluctuations of a fluid; a housing defining an inner
volume though which the fluid is permitted to traverse from a first
opening to a second opening, and generating vibrations in the
housing from the increased fluid fluctuations which are then
harvested from the generated vibrations.
[0008] Further features and advantages of the invention will become
more readily apparent from the following detailed description when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is further described in the detailed
description which follows, in reference to the noted plurality of
drawings by way of non-limiting examples of exemplary embodiments
of the present invention, in which like reference numerals
represent similar parts throughout the several views of the
drawings, and wherein:
[0010] FIG. 1 illustrates a schematic view of an energy harvesting
device downhole;
[0011] FIG. 2 illustrates a schematic view of an energy harvesting
device located at the end of a production tubing;
[0012] FIG. 3 illustrates a schematic view of an energy harvesting
device in a well with artificial lift;
[0013] FIG. 4A illustrates a graph of power variation as a function
of time and FIG. 4B illustrates a graph of displacement of a
production tubing as function of time;
[0014] FIG. 5 illustrates a further embodiment of an energy
harvesting device;
[0015] FIG. 6 illustrates a power generating assembly with axial
displacement;
[0016] FIG. 7A-7B illustrates a power generating assembly with a
vibrating sleeve; and
[0017] FIG. 8 is a flow chart illustrating an embodiment of the
disclosed subject matter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The particulars shown herein are by way of example and for
purposes of illustrative discussion of the embodiments of the
present invention only and are presented in the cause of providing
what is believed to be the most useful and readily understood
description of the principles and conceptual aspects of the present
invention. In this regard, no attempt is made to show structural
details of the present invention in more detail than is necessary
for the fundamental understanding of the present invention, the
description taken with the drawings making apparent to those
skilled in the art how the several forms of the present invention
may be embodied in practice. Further, like reference numbers and
designations in the various drawings indicate like elements.
[0019] Embodiments of the present disclosure may be implemented in
various different devices for converting kinetic energy from the
surrounding environment into electrical energy. The embodiments are
described below in the context of the source of kinetic energy
being fluid flow through a borehole such as those associated with
petrochemical wells. Additionally, it is to be understood that the
various embodiments of the present disclosure described herein are
not limited to petrochemical wells.
[0020] Apparatus and methods are disclosed for enhancing the
efficiency of downhole energy harvesting devices. In one embodiment
an apparatus and method is disclosed for enhancing the efficiency
of downhole energy harvesting devices in reservoir completions that
use artificial lift to generate the flow of producing fluid. The
efficiency of the downhole energy harvesting device is enhanced by
modulating the input power to the artificial lift device. In one
non-limiting example the artificial lift device is an electric
submersible pump. Modulating the input power to the artificial lift
device creates fluctuations in the producing flow at a
predetermined frequency or group of frequencies. The amplitude of
the flow fluctuations is small enough so as to minimally affect the
production. The frequency or frequencies are selected in one
non-limiting example in accordance with the frequencies at which
energy harvesting devices placed downhole in the reservoir operate
at their maximal efficiency and/or generate maximal energy. In one
non-limiting example the frequencies are selected to match the
resonance frequency or frequencies of one or more energy harvesting
devices.
[0021] Representatively illustrated in FIG. 1 is a method and
apparatus which embodies principles of the present disclosure. The
method and apparatus are described herein as being performed in one
non-limiting example in conjunction with a producing well in which
fluid is produced from a formation 111 into a tubular string 113 to
the earths' surface. A downhole module 109 comprises an energy
harvesting module. This energy harvesting module converts the
kinetic energy of a fluid flow 103 in a borehole 115 into
electrical energy. In one non-limiting example the downhole module
109 further comprises a flow monitoring module and a flow control
module. In one non-limiting example the flow monitoring module will
monitor downhole production conditions, power, temperature, flow
and water cut. In one non-limiting example the flow control module
may comprise inflow control valves.
[0022] In the illustrated embodiment, fluid flows through a
cylindrical (tubular) housing 113 having an inlet and outlet.
Kinetic energy associated with the fluid flow causes structural
vibrations due to flow fluctuations. These structural vibrations
are an important source of harvestable energy for downhole power
generation. Flow fluctuations can occur in many geometric
configurations and in one non-limiting example the end of the
production tubing is, in many cases, a cantilever beam geometry. In
one non-limiting example fluctuation in the flow is created by
oscillating power 101 to a pump 107. In the illustrated embodiment
the pump 107 is part of an artificial lift system utilizing an
electric submersible pump connected with a control line 117 to a
power supply 101. Artificial lift systems are used for moving
wellbore fluids. Some wells are capable of producing under
naturally induced reservoir pressures but more common are wells
that employ some form of an artificial lift production technique.
The pump 107 is disposed along the cylindrical (tubular) housing
113 but downstream to most laterals or complex architectural
features.
[0023] FIG. 2 illustrates a schematic of a geometry for the end of
a production tubing 203. Packers 211 anchor the production tubing
203 to a casing 209 while fluid flows 207 into the production
tubing 203 thus creating a cantilever which is free to vibrate.
Packer 211 is positioned to seal the annulus between the production
tubing 203 and wellbore casing 209. Fluid flows 207 into the
production tubing 203 creating flow fluctuations which causes the
cantilever to vibrate at a certain frequency. An optimal position
for an energy harvester module 205 in one non-limiting example is
close to the tip of the production tubing 203 where the amplitude
of vibrations is the greatest. The production tubing 203 vibrates
at the system natural frequency but the amplitude of oscillations
is very small which limits the amount of energy harvestable.
Embodiments of the present disclosure enhance the energy available
for harvesting and therefore the power produced by modulating the
fluid flow to match the frequency of the tubing vibrations. This
will increase dramatically the amplitude of the production tubing
oscillations.
[0024] FIG. 3 illustrates one embodiment of the present disclosure.
A wellbore 317 is generally illustrated having a primary borehole
321 and a lateral borehole 319. It will be appreciated that
additional laterals may exist in an actual wellbore and that this
drawing merely illustrates a small portion of the overall wellbore
system. Wellbore 317 includes a casing 315 disposed therein. Packer
305 is positioned to seal the annulus between the production tubing
307 and wellbore casing 315. A pump 301 is disposed along the
cylindrical (tubular) housing 307 but downstream to the lateral
borehole 319. The energy harvester 303 is disposed along the
cylindrical (tubular) housing 307. The pump 301 is connected to the
power module 101 on the surface via a control line 313. Embodiments
of the present disclosure oscillate power from the power module on
the surface to the pump 301. These oscillations produce
fluctuations in the flow rate which can be felt upstream where no
power connection is present e.g. at the energy harvester module
303. These fluctuations can be matched to the natural frequency of
the cylindrical (tubular) housing 307 to increase the magnitude of
displacement of the cylindrical (tubular) housing 307 thus
enhancing the energy available for the energy harvesting module 303
to harvest. The advantages of embodiments of the present disclosure
are that a much greater amount of energy can be harvested with very
little effect on the overall rate of production.
[0025] FIG. 4A illustrates a graph of power variation as a function
of time. The power module 101 varies power to the pump 301 where
the power variation in one non-limiting example is a slight
variation and distributed around an average value. The frequency of
the variation is matched to the frequency of the instability
experienced by the cylindrical (tubular) housing 307 upstream. FIG.
4B illustrates a graph of tubing displacement 307 as a function of
time.
[0026] FIG. 5 illustrates a further embodiment of the present
disclosure. The energy harvesting module 506 is disposed along the
cylindrical (tubular) housing 503. Flow fluctuations are generally
not present at the location of the energy harvesting module 506 in
the illustrated figure. Vibrations can be excited by the flow
fluctuations from a pump similar to the pump 301. FIG. 5
illustrates a cylindrical (tubular) housing 503 supported on both
ends with flow through it. The cylindrical (tubular) housing 503 is
anchored to the casing 505 at the two extremes and the cylindrical
(tubular) housing 503 vibrates as the fluid flows through it.
[0027] A further embodiment of the present disclosure comprises
harvesting vibrations which are generated from displacement in the
axial direction rather than the lateral direction. As disclosed in
application Ser. No. 12/479,308, filed Jun. 5, 2009, entitled
"ENERGY HARVESTING FROM FLOW-INDUCED VIBRATIONS", which is herein
incorporated by reference, a small obstacle can be placed at the
entrance to a production tubing. This obstacle creates shedding of
vortexes at a certain frequency.
[0028] FIG. 6 illustrates a power generating assembly 615 which
undergoes oscillations due to the induced force from vortex
shedding. A mass-spring system 613 is attached to an obstacle 611.
The mass 603 of the power generating assembly 615 undergoes
oscillations. The mass-spring system which is attached to the
obstacle 611 in one non-limiting example has a resonant frequency
which matches the vortex shedding frequency. The axial oscillations
of the mass-spring system 613 can then be harvested by an energy
harvesting module downstream. The displacement of the mass-spring
system 613 can be increased by modulating the flow and in one
non-limiting example by modulating the flow with a pump similar to
pump 301. The frequency of the pump 301 can be modified to match
the resonance frequency of the mass-spring system. It is to be
clearly understood that principles of the present disclosure may be
incorporated in other methods and apparatus to enhance energy
production of energy harvesting modules, for example, methods and
apparatus of the present disclosure may enhance energy production
of energy harvesting modules whose design is based on vibrational
energy harvesting.
[0029] FIG. 7 illustrates a further embodiment of the present
disclosure. The vibrating sleeve design was disclosed in
application Ser. No. 12/479,308, filed Jun. 5, 2009, entitled
"ENERGY HARVESTING FROM FLOW-INDUCED VIBRATIONS", which is herein
incorporated by reference. This vibrating sleeve 701 can be placed
anywhere along a production tubing 709 and can have in some
non-limiting examples two slots which may be aligned or offset or
in one other example four slots as illustrated in FIG. 7A-7C. The
vibrating sleeve apparatus 701 creates sustainable oscillations by
opening and closing access to the production tubing 709 and
therefore controlling the pressure drop on opposite sides of the
vibrating sleeve apparatus 701. The energy harvesting mechanism is
enhanced by flow modulation with the flow fluctuation frequency
matching the resonant frequency or frequencies of the vibrating
sleeve apparatus 701.
[0030] In a further embodiment of the present disclosure a method
and apparatus of enhancing the efficiency of energy harvesting
modules comprises a plurality of frequencies. A plurality of
frequencies can be excited by controlling power to a pump so that
specific energy harvesting modules located in geometries that
oscillate at different frequencies may oscillate at the same
time.
[0031] In an alternative embodiment one or more of the plurality of
energy harvesting module may be tuned to a different frequency. In
a downhole environment power is needed to perform many tasks e.g.
provide power to sensors or actuators. The pump may be modulated to
match the frequency of a specific harvester module which provides
power to a specific sensor or actuator. The advantage of this
system is that power is harvested and generated only in the
location needed and only when needed therefore modulation of a pump
is only intermittent as needed.
[0032] In an alternative embodiment a flow restrictor creates flow
fluctuations. In one non-limiting example the flow restrictor may
be placed upstream or downstream of an electric submersible pump.
However, it is to be clearly understood that the flow restrictor
may also be used where flow rates are relatively large and no
artificial lift system is necessary. In one non-limiting example
the flow restrictor may be modulated to an energy harvesting module
to create resonance and therefore enhance the efficiency of the
energy harvesting module. To avoid a substantial pressure drop
across a flow restrictor, in one non-limiting example the flow
restrictor restricts only a small percentage of the production
tubing area.
[0033] The energy harvesting module may harvest energy from the
generated vibrations using any standard mass-spring system. In one
non limiting example the energy from the vibrations may be
harvested by using a mass-flexures system which was disclosed in
application Ser. No. 12/366,119, filed Feb. 5, 2009, entitled
"ELECTROMAGNETIC DEVICE HAVING COMPACT FLUX PATHS FOR HARVESTING
ENERGY FROM VIBRATIONS", which is herein incorporated by reference.
To maximize the energy harvested the resonance frequency of the
energy harvesting module and the pump modulation frequency can be
matched to the system natural frequency.
[0034] FIG. 8 illustrates a flowchart of an embodiment of the
subject matter disclosed. A power generating module 801 disposed on
a production tubing generates vibrations in response to flow
fluctuations. A modulator module 803 modulates in one non-limiting
example a modulation signal so as to cause flow fluctuations 805 in
the producing flow at a predetermined frequency or set of
frequencies. The increase in flow fluctuations 805 creates an
increase in vibrations 807 of the power generating device 801. This
energy is harvested upstream 809 and used to power flow monitoring
or flow control devices 811.
[0035] Whereas many alterations and modifications of the present
invention will no doubt become apparent to a person of ordinary
skill in the art after having read the foregoing description, it is
to be understood that the particular embodiments shown and
described by way of illustration are in no way intended to be
considered limiting. Further, the invention has been described with
reference to particular preferred embodiments, but variations
within the spirit and scope of the invention will occur to those
skilled in the art. It is noted that the foregoing examples have
been provided merely for the purpose of explanation and are in no
way to be construed as limiting of the present invention. While the
present invention has been described with reference to exemplary
embodiments, it is understood that the words, which have been used
herein, are words of description and illustration, rather than
words of limitation. Changes may be made, within the purview of the
appended claims, as presently stated and as amended, without
departing from the scope and spirit of the present invention in its
aspects. Although the present invention has been described herein
with reference to particular means, materials and embodiments, the
present invention is not intended to be limited to the particulars
disclosed herein; rather, the present invention extends to all
functionally equivalent structures, methods and uses, such as are
within the scope of the appended claims.
* * * * *